.geo was a generic top-level domain proposed by SRI International to be used to associate Internet resources with geographical locations, via a system of "georegistrars" and "georegistries" with hierarchical addresses representing locations in a grid encircling the Earth. These addresses are not intended to be typed in directly by end-users (and hence are "messy" strings like acme.2e5n.10e30n.geo) but rather, would be used "behind the scenes" by software looking things up by location (possibly driven by GPS positioning in mobile devices).

a Uniform Resource Identifier (URI) for geographic locations using the 'geo' scheme name. A 'geo' URI identifies a physical location in a two- or three-dimensional coordinate reference system in a compact, simple, human-readable, and protocol-independent way.